Elemental absorption

An ongoing research project between Kettering University and a federal contracting corporation yields new results regarding the diffusion of chemical elements into porous materials such as porcelain tile, thus marking yet another important point of success.

In a physical sense, we are fragile creatures. Bones can snap like twigs under the right conditions. Our joints degrade after years of punishing labor and eventually turn into a pulpy mush. And just how many other creatures can obtain cuts simply by running their fingers along the edge of a piece of paper?

Unfortunately, our senses are also easy marks for those who wish to maim or even kill people. As news broadcasts indicate each night, terrorists continue to threaten the general population. These individuals are continuously looking for ways to victimize human vulnerabilities and often research how elements can subtly injure or kill large quantities of people without immediate detection.

For Kettering University's Dr. Homayun Navaz, this concern is at the root of the Chemical Agent Fate Research Program, a project funded through a $2.9 million research contract from a federal contracting corporation. The thrust of this effort is to develop computer models that predict the dispersion and persistence of a chemical in the air and ground after it is deposited, and determine how long a chemical compound remains active after its release. The mathematical analyses associated with this project will greatly enhance the capability to computationally simulate possible scenarios and aid officials in taking preventative actions.

These mathematical models, Navaz said, are currently undergoing validation with calibrated data, thus increasing "our confidence in their prediction capabilities." The idea is to protect human life by converting highly technical science and experimentally validated mathematical modeling information into a usable tool for military organizations and the general population. The computer models will aid military forces to better protect themselves and operate in contaminated environments.

Themodels predict such things as the dispersion of elements through aporous substrate and the simultaneous phenomenon of a chemical reaction of an agent. The ultimate objective of this project is to help predict the fate of a chemical agent after it is deposited on the ground and on other surfaces, and offer an engineering tool to present temporal and spatial information about an agent's fate.

The project, according to Navaz and his contacts at the federal contracting corporation that funded the effort, has progressed extremely well. Currently, he and his associates are working on two types of modeling: Continuum and Discreet. Both models examine how chemical elements sink into certain surfaces and the time required for this diffusion. "We've validated the model with running tests on household tile using oil and water, depending on the viscosity and surface tension of the liquid," Navaz said. These models will also undergo validation with actual data taken in certified labs from around the world.

Thus far, Navaz said that the model predictions are satisfactory "This is a good start," he said, adding that developing a model like this is sort of like raising a child: "It evolves from infancy to maturity, and the first few years of development are so important."

He also said that this is the first time that researchers are using a mathematical and numerical algorithm to solve such a problem. "The success of these modules relies on their robustness and the fact that they are modular," he explained. "As more advanced modules become available, they will easily undergo incorporation into the program without the need to modify the solver (or engine)," he added. The nice thing about this particular model is that it allows researchers to input any kind of fluid properties, thus making it more flexible in terms of predicting how other liquids, such aspesticides andoil, might penetrate surfaces.

Navaz is currently developing the Continuum Model while his post-doctoral fellow assigned to this project, Dr. Boyan Markicevic, is working on the solution to the mathematical equations based on a discreet approach. Together, these models provide "a parallel approach for comparisons to yield comprehensive results. The idea is to give the contractor a model that is as useful and flexible as possible at the present time and for future needs. In the long run, this will help tremendously, especially since these models are user-friendly," he said.

Navaz is quick to recognize the invaluable assistance of other faculty members who helped make this part of the research such a success, including Drs. Ali Zand and Yuri Sikorski from the Chemistry and Physics Departments, who were involved in the experimental validation of the model. Dr. Matthew Sanders of the Industrial and Manufacturing Engineering Dept. is helping to manage the work of cooperative education students working on the project. These students include Chemistry Major Elizabeth Cox, a sophomore from Monroe, Mich.; Senior Ewen Chan from Toronto, Ontario; Industrial and Manufacturing Engineering Major Renee Hughes from Fenton, Mich.; and Computer Science Major Aaron Grady from Chicago, Ill. All, Navaz said, are providing invaluable contributions to this original research project.

This computer model represents the absorption of a chemical element of into a piece of ceramic tile. The chemical took approximately 50 minutes to absorb into the tile.